Method of and apparatus for gasifying a liquid fuel



Dec. 1937. c. A. KILLMEYER El AL 2,102,800

I METHOD OF AND APPARATUS FOR GASIFYI NG A LIQUID FUEL Fil ed Dec. 12, 1934 3 Sheets-Sheet l INVENTORS CHESTER A. KH-LMEYER GBE$RGE L- RE\CHHELM ATTORNEY D 21, 1937 CA. KILLMEYER ET AL 2,102,800

METHOD OF AND APPARATUS FOR GASIFYING A LIQUID FUEL Filed Deb. 12, 1934 s Sheets-Sheet 2 INVENTORS CHESTER A. KILLMEYER GEORGE L. REICHHELM AAAAAAAAAAAAh/l ATTORNEY "5 Sheets-Sheet 3 Filed Dec. 12 1934 C. A. KILLMEYER ET AL METHOD OF AND APPARATUS FOR GASIFYING A LIQUID FUEL Dec. 21, 1937.

Patented Dec. 21, 1937 UNITED STATES PATENT OFFICE METHOD OF AND Arimwrus Eon GAS!- FrmG A LIQUID FUEL Chester A. Klllmeyer, New .York, 'N. Y., and

George .L. signers to City, N. Y

Belchhclm, Short Beach, Comm, as-

Frank A. Kane, Long Island Application December 12, 1934, Serial No. 757,092

13 Claim.

This invention relates to a method of and apparatus for gasifylng a liquid or plastic fuel, its primary object being to form therefrom a homogeneous gaseous fluid for use in various types of combustion devices. In preparing either ternal combustion engines and burners, the method universally employed consists of transforming the liquid into a vapor or mist by more or less liquid or plastic fuels for combustion purposes, particularly for use in inconventional atomizlng or vaporizing devices, and

then combining the -resultlng:spr'ay-with air'to obtain a mixture in explosive proportions. It is the obvious aim of every atomizing device of this class, such as carburetors and the like, to produce as fine a'spray as possible; but even in the most efficient devices of this kind, where an exceedingly finely-dividedspray is obtainable, the I fuel stream isneve'rtheless composed of air-carried liquid particles, constituting "a'mixture that;

lsnoticeably wet particularly at the relatively low intake manifold temperatures of internal com busti'on, engines. In conceiving. this" invention it was our purposeto improve upon? this conditi'om and to" effect a finer degree ofpulverization oi the liquid than has ever'heretofore been obtained;

and in a mechanical embodimentpf our invention and the processemployed thereby we have sue-1 ceeded in obtaining from hydrocarbons; and from relatively heavy and low-volatile fuels, in accordance with one of our objects, a product that is orihas every apparent characteristic of a'homogeneous fixed gas,-oneewhigh is invisible and substantially dry at intake; manifold temperatures;- Although some attempts have'been made in thepast to gasify liquid fuels, the nature of the means employed therefor necessitated; the' use of fuel t e'ssential step; thedirectihgflof "a; spray of liquid fuehfinduced in part by'a' continuous current; orpiratprm mg Y mediunnsuch' as preheated,

air; into a "now conduit tempting; a longitudinal series or tubes or ucces'siifely increaslng diameters, with overlapping adjacent ends in fixed telescopic arrangement, the tubes being preferably of the Venturi type and the said overlapping. ends being in spaced relation to form circumferential gaps therebetween. The said current of preheated air is then caused to pass about and along the outer peripheral surfaces of the first few tubes in substantially cylindrical concentric V streams, entering a predetermined number of said circumferential gaps to commingle with the inner fuel stream, thereby effecting an interpenetration of the constituents of said latter stream with that of fresh currents of heated air at a' number of points. A continuous fresh stream of relatively cold air is then introducedialong the succeeding peripheral surfaces of the last few" tubes to enter the remaining ofsaid gaps and similarly co'mmingl'e with the inner, stream, thereby diluting it a predetermined amount in accordance with combustion requirements.

The fuel stream,'during its path of travel through the tubes, successively passes through a plurality 'of intensely; evaporativeregions of local vacuum at the, constricted portions of 'tlie venturis,. with resulting lowered boiling points and the consequent complete gaslflcation of'any suspended fuel particles by the heat in saidconce'ntrio streams of air. The temperature of the fuel in its initlalliquid form is below its ev'a'por'atiorif range,. so that no fractional distillation takes place at the beginning of the process; bu'tthe pr heated air. (or other hot atomizing fluid), however, is of a temperature above the boilingipoin't of any of the constituentsyof the fuel at the reduced pressures prevalent at, the' throats of' the tubes, assuring 'complete'gasificatlonwhen the fuel stream haspassed a'number of venturis. This gasifying'actionis materially ,aidedlbya pulsating efl'ect throughout the fuel stream, produced by the alternate contraction and expansion of .the-streamancl its periodic changes in ve-- locity due to the successive variationsiri 'crosssectional area 'of the tubes the heat-transfer influence of the injected air,-"-'-thereby creating such interpenetration, turbulence and molecular impact within'the gas as to make for homogeneity. Thefuel stream, as stated, is subjected to successive expansion stages, which, together with the'efiect of the cooling airintroduc'ed as afore said, results in a relatively ,mw gas temperature at-the outlet of the .device j-below the' vapor condensation point of the gas at the prevailing nre sur ea m 1 1 mwn am in ern abastion, engines; is" obviously conducive to'high vol im i f c efficiency.

ture, and is adapted to produce a hydrocarbon gas in various degrees and proportions of fixity, which is in accordance with another object of our invention.

Another object of this invention is to generate a gaseous fluid from a heavy as well as a light fuel oil with such rapidity as to produce a practically instantaneous gasifying action, a feature invaluable in starting internal combustion engines at low temperatures.

Still another object of this invention is to automatically vary the relative proportions of the gaseous fuel and a fluid suchv as air, thereby ob taming a predetermined fuel ratio over any required range in conformity with the demands of the fuel-consuming device, such as an internal combustion engine, a gas burner or the like.

A further object is to produce an apparatus for employing the -above-described process which is sufllciently compact as to be adaptable for use on motor cars and other places where space economy is an important consideration.

And another object of our invention is to effect a cracking of fuel oil by means of our said process, a result which is obtained by employing a preheating medium (used in conjunction with a step of the process) of a temperature sufiiciently high to accomplish this purpose for the fuel used.

Other objects, features and advantages will appear from the drawings and the description hereinafter given.

Referring to the drawings,

Figure 1 is a vertical sectional view of the principal unit of one form of apparatus employing the process constituting part of this invention.

Figure 2 is an enlarged sectional view of a portion of the apparatus of Figure 1, illustrating the paths of the fuel and air streams.

Figure 3 is a sectional view of the spraying portion of another form of our apparatus, showing a single venturi with a serrated outlet edge.

Figure 4 is a view similar to Figure 3 showing a modification with a two-stage venturi.

Figure 5 is a sectional view of another form of our invention showing a multi-stage venturi all the tubes of which have serrated terminals, this arrangement showing an atomizing and a cooling section.

Figures 6 and 7 represent a sectional elevation and plan view respectively of a fuel jet with a smooth peripheral outlet edge, 'adapted for use with our apparatus.

Figures 8 and 9 show a section and plan respectively of a jet with a serrated edge.

7 Figures 10 and 11 are sectional and plan views respectively of an oil jet with a slotted wall.

Figures 12 and 13 are sectional and plan views respectively of a jet with a combined slotted and serrated outlet portion.

Figure 14 is a fragmentary sectional view of a combined jet and spray device adaptable as an adjunct to the apparatus constituting part of this invention.

Figure 15 is a sectional view of another form of oil spray jet.

Figure 19 illustrates a form ofheat exchange The above-described process is flexible in naapparatus for preheating the atomizing air, comprising an exhaust pipe of an internal combustion engine surrounded by an air supply jacket.

In the drawings, the casing 30 contains therein the flow conduit 3| comprising a plurality of tubes 32, 33, 34, 35, 36, 31 and 38 of successively increasing diameters and preferably of the Venturi type, these being longitudinally disposed with overlapping adjacent ends to form a plurality of circumferential gaps 39, 40, 4|, 42, 43 and 44. The said flow conduit 3! is divided into two sections by the partition 45, said partition being so arranged with reference tothe tubes, in the particular design shown, that the said gaps 39 and 40 are contained within the atomizing inlet 46, and the remaining gaps are contained within and communicate with the combustion air inlet 41. The said inlets 4S and 41 are provided with suitably controlled valves 48 and 49 respectively. The fuel nozzle or jet 56 is operatively adjacent the inlet to the tube 32, said jet being supplied with fuel drawn in through pipe I which extends into the float bowl 52,-the needle valve 53, controlled by the adjustment screw 54, being operatively engageable with the inlet terminal of pipe ii. The said flow conduit'll communicates either with a combustion chamber of a burner or with an intake manifold of engine 55 through the valve 56. It will be noted that in the apparatus disclosed in Figure 1 the first three tubes have serrated outlet edges, the balance of the tubes having their corresponding outlet edges of smooth configuration.

contemplation of our invention to employ venturis with any predetermined number of serrated outlet edges, depending upon design and engineering requirements, such as the apparatus of Figure 5 where all of the venturis 5a, 5b, 50, Id, 5e, and 5) are shown with serrated edges. And it should be further noted'that the flow conduit 3| of our invention need not necessarily be divided into two sections by a partition such as the wall 45 requiring the use of two fluid mediums, as a single fluid medium can be employed within the scope of our invention, for ordinary carburetion purposes, as indicated in Figure 2, and such a construction can be employedin a down-draft device with the flow conduit extending vertically as shown in Figure 5.

Although the flow conduit referred to in the drawings and description herein comprises mainly wenturis of substantially cyiindrcal shape, other forms of tubes can be employed within the scope of this invention, such as those of conical configuration or of square or rectangular crosssection. Also, instead of circumferential gaps in planes normal to the conduit axis, helically disposed gaps or other forms of inlet ports can be employed within the intent of our invention.

The spray nozzle 56 may be of the design illustrated in Figures 6 and 7 with a smooth terminal edge 6a; or it may be one having serrated edges in such as is shown in Figures 8 or 9. In Figures 10 and 11 is shown a spray nozzle the sides of which contain a plurality of slots lla,--and in Figures 12 and 13 another form of nozzle is shown, combining the features of a serrated and slotted nozzle wall, and containing the slots a and serrations I21). v

.. Inthe operation ofjthis device, a flow of fuel is induced through the nozzle Iii into the tube 5 i 32,the amount of said fuel being regulated by the needle valve BI. A heated medium, such as air suitably preheated, is caused'to flow through the valve 48 and inlet 46 to enter the tube 32, thereby serving tov forman atomized fuel stream 10 within the flow conduit II. The said atomizing I medium or preheated air also passes over and surrounds the tubes 32 and I3, entering the gaps 38 and Q to commingle with the said fuel stream within the multi-tube conduit. In the. form of 15 our invention shown in Figure 1, relatively cold combustion air is caused to enter the inlet 41 through the valve ",such air similarly entering the gaps ll, 42, 48 and 44 to further commingle with the fuel stream which. is headed to enter 20 the intake manifold of engine 5! through the valve 56. Reference to Figure. 2 will show the I paths of flow of the various fluid streams. v The term combustion air as herein employed is used to identify the unheated and uncontami- 25. nated fluid medium entering the flow conduit through inlet 41, a'sjdistinguished from the fluid medium entering through inlet 46. Although the latter. fluid generally also contains combustion air, it serves the primary purpose of an initial 3(ia .tomizing medium, being preferably preheated,

. and at times mixed .or contaminated with a hot .gaseousfluidr' I ,An analysis of the action within this appara- -tus will disclose, as will be more specifically here- 35 inafter pointed out, that the method employed thereby, embodies several steps all -of which coact combinatively to convert a liquid fuel intoja gas and to impart thereto the properties of combustiming-homogeneity and such low temperature -l0, characteristics as are conducive to high volumetric; efliciency. Thesaidsteps are both mechanical and thermodynamic in nature,- the 'inecham Mical steps 7 comprising, or effecting (a) induced ;-.ej,ection of-the liquid fuel, (b) atomization there- 5 g of by, a: ,fluid medium such as air, dispersion --from the peripheral terminal edge of thew-fuel nozzle. and from; aplurality; "of successive edges 7 or pointsalong the path of. travel of the fuel 1 stream; (4) --interpenetrationof -a number of fluid 0 streams-with the. innerfuel' stream due to their u intersecting paths of travel. (e) molecular disturbance and turbulence within the fuel stream .j-due to variations inthe cross-sectional areas of 1. the flow conduitand to the @consequent changes 55 -in velocity and-successive contractions and expanersions of the fuel-streamalongits path ofitravel, f ifilsradiml and progressivedilution of thelfuel stream at difierent points along its.v pathi with tresh sup i zflrs 19mm; t mi med u da 60 then of theeombustion air, (9)1 an d,progressive e pa i n i uel. st eam as d. by the; m

I q creasing cross-sectionalarea of the flow "conduit;

. and the said thermodynamicsteps comprising or eife cting '(h) "a'direct manager the fuelstream {6:5 with jconsequent"increased" 'liin'eti'c energy and turbullenqe'within inasnamprh alternate con traction and: expansion-or the fuel stream at a,

l constricted portions or threats of the flow conforwardly from the peripheral terminal edge thereof. Where a spray nozzle having a serrated edge such as 84 disclosed in Figures 8 and 9 is employed, the liquid is torn from each of the many points on the skirt of the no e, thereby resulting in a spray considerably finer than would be the case where the liquid were ejected from a smooth outlet terminal or one with relatively few points. Where the nomle of Figures 10 and 11, or of Figures 12 and 13 is employed, the slots in the wall of the nozzle present agreater outlet surface for the liquid fuel being elected, thereby effecting a greater degree of initial atomization. As the fuel stream continues through the flow conduit, it must necessarily pass each of the terminal ends of the longitudinally disposed venturis,-and where these terminal edges are also serrated, there will be a still greater atomizing effect, inasmuch as any liquid particles that may collect thereon willbe torn from a great plurality of points to produce a greater degree of pulveri- 0 zation. j

It will be notedthat the streams of atomizing fluid or air surrounding the Venturi tubes, in entering through the circumferential gaps there; between, follow a path intersecting that of; the direction of flow of the inner fuel stream (see Figure 2), thereby causing an interpenetration 'ofthe entering fluidwith said inner stream,a condition which is considerably enhanced by the fact" that; the entering fluid is injected into :a 40 fluid traveling at a relatively high velocity due to'the constrictions of the ventu'ris at the throats thereof. Such interpenetration is quite obviously conducive to a greater pulverizing effect. The

' sectional area of the flow conduit throughout the length thereof, inasmuch as said stream m'ust successively 'passthrough a series of-Venturi constri'ctions; and such cross-sectional variations 5 produce velocity changesand successive expan- "sions and contractions of the stream- 'bringing about a considerable internal disturbance to effect a thorough mixing. A

Another very'impo'rtant factorin this gasifying process is the" method of gradual dilution of the ful stream with the-'mixingfliiid simultane-' o i ly injected at anumber-ofdifferent points especially when "there is" first the introduction of 'the j'atb mi-zing medium such as prehatedair though the fi is't series of gaps, and'then the introduct'ionjof secondary or unheated combustion "air'thr'ough the'rer naining-gaps. At each of said sets a stage in t ns gradual di1ut'ionprocess is effected, and-at each stage "there is introduced-a 5 fraction of the" entire-predetermined amount of fluid required. methodof gradual diiution th iiitlr odtlctib'ii or the fluid in installments nie hddof cdntmuouslylntrod cing a fluid'me- .lfldium: such a prehe'atedairfand combustion air .has the further, advantage of supplying "to the fuel tream, at fe cn :p iht r injection," charges of relatively" fresh and uncontaminatedair, 1

which is always preferred for combustion purposes.- And by employing this method, no stratiflcation of air in the fuel stream will take place, such as generally occurs when all the combustion air or other fluid medium is introduced at one time in one local region.

Each successive venturi, as can readily be seen, is of greater diameter than the preceding one, thereby constituting a gradually expanding flow conduit 3|,an arrangement which permits of the progressive expansion of the fuel stream with a resultant relatively low temperature at the intake manifold, a condition which is aided by the heat-transfer'effect of the cooling air introduced through valve 49. From tests which we have conducted, we have noted temperatures in the intake manifold considerably below the condensation point of the gaseous fuel fluid, without any visible evidence of precipitation,-the fluid being absolutely invisible. This low temperature,

' which is obviously conducive to high volumetric eiflciency as hereinbefore stated, is due in part to the relatively low temperature of the incoming combustion air, but is primarily brought about by the refrigerating effect of the successive expansions of the fuel fluid stream in passing through the venturis.

Another advantage of employing venturis with serrated terminals positioned in the throats or restricted regions of succeeding venturis is the readiness with which the venturis can be adjustably positioned for best operation. It is evident that the roots and apices of the serrations in a given venturi are situated in two different planes, presenting outlet edges extending substantially longitudinally of the flow conduit. 'The arrangement hence is-not as critical as would be the case in a venturi with a smooth terminal edge, inasmuch as the serrated edge can be moved slightly in a longitudinal direction without materially affecting the results, provided the said outlet edges are within the region of the throat of the venturi. Hence in such a construction non-fluctuating pressure conditions can be more readily attained, with a consequent steady flow of the fuel stream.

Other essential factors which are accountable for the gasifying action of our process relate to the effects of prevailing heat and pressure conditions therein. It is well known that the preheating of the fuel stream will aid the pulverization process by virtue of the greater internal molecular activity generated within the stream; and as a heated fluid is introduced into the fuel stream through valve 48, such action is effected in our apparatus. Furthermore, the introduction of atomizing and combustion air fluids of varying temperatures through the gaps between the tubes causes a heat exchange to take place at each region where there is a gap, resulting in an expansion of the heat-absorbing fluid and a contraction of the heat-emitting fluid. Inasmuch as both of these co-mixing fluids are con-. tained within a confined portion of the flow conduit, this simultaneous expansion and contrac-. tion of both fluids will cause a very desirable condition of intermingling. I

From actual tests which we have conducted, we have found that the depression 'at the throat of the first venturi 32 is considerably in excess of the manifold depression. the depressions at thethroats of the intermediate venturis being in proportion. As a matter of actual experimental observation, we have noted that with a manifold depression of 3" of Hg the depression at the.

.action being practically instantaneous,

choke band. of venturi 32 is approximately seven times as great. It is hence obvious that the boiling point of the fuel at the constriction in venturi 32 is materially lowered beyond its.normal atmospheric value. Inasmuch as the preheated fluid entering through the valve 48 is limited only to temperatures which will disintegrate or adversely affect the metals constituting this device, such temperatures can be relatively high since such metals can be of high heatresisting properties. It is therefore obvious that the incoming fluid through valve 48 can be of sufllciently high temperature to completely evaporate any liquid particles of oil suspended at the low-pressure region of the throat of venturi 32; and this applies to a wide range of fuels including those of heavy and low volatile characteristics, such as are used in furnaces for domestic heating and industrial purposes. If the temperature of the incoming fluid is greater than the end point of the.fuel at the prevailing low pressure within the venturi, it is apparent that there will be a complete evaporation of every particle of liquid, without any fractional distillation whatsoever. Any surface tension of the fuel or liquid particles constituting same which may tend to resist gasiflcation will be completely counteracted by the shocks imparted to the fuel stream by the repeated suddenchanges to low pressure conditions at the Venturi constrictions.

From the above detailed description of the mechanical and thermodynamic actions within our apparatus, as effected by the steps of our process, it becomes obvious that a fuel stream is generated thereby which is subjected, at a number of points along its path of travel, to manifold gasifying conditions, resulting in a fixed homogelar fuel used, an actual cracking of the fuel will be effected. Furthermore, it is apparent that the entire gasifying or cracking process takes place within a relatively small space,the entire and hence operably effective with both heavy and light fuels at exceedingly low temperatures.

It should be noted that although the term liquid fuel is repeatedly" referred to, throughout this specification and the claims hereinafter set forth, as the fuel to be converted to a gaseous fluid by means of this invention, it is in the broader sense that this term is used, the intent being to include in its category colloids and plastic fuels as well.

In order to effect a more eflicient initial atomi-.

zation, we have conceived the modified form of combined spray and nozzle illustrated in Figure 14, as an adjunct to this apparatus. In this modification the double opposed spray nozzles 51 and 58 are operatively positioned adjacent the openings of the venturis 59 and 60 respectively. Intermediate said venturis is an auxiliary air supply duct 6| which introduces a supply of air transverse to the direction of flow of fuel through said nozzles. when the opposing streams from these nozzles meet, and the combined stream is diverted downwardly through the venturi 62, a greater soaking period is obtained, due to the time consumed in effecting this directional change and neous gas that is relatively dry at manifold prestion, all the cooling air would be excluded, and

the further factthat as said opposing streams approach each other their-velocities become considerably reduced. To effect still greater initial atomization the stream of air injected through the duct 8| is heated, imparting to the combined stream an additional amount of heat beyond that supplied by the initial atomizing air.

Another modification of spray nozzle is illustrated in Figure 15 in which the two funnelshaped walls 88 and 84 form therebetween afunnel-shaped space 85 into which the oil from supply tube 68 enters to be discharged through the peripheral opening 81. Atomizing air, preferably preheated, is fed into a tube 68 and discharged through orifices 88,-this air not only assisting in heating the fuel oil pulverized from the outer serrated edge of the nozzle, but also serving to eliminate the vacuous zonecreated in the hollow of the cone. With this design, the fuel oil is kept confined to the outer peripheral edge of the nozzle, thereby insuring a finer degree of atomization than could be effected if some relatively large particles of liquid fuel were permitted to drop through the center of the cone.

In order to vary the proportion of the atomizing medium such as preheated air to the cooling medium such as combustion air, we have provided the flow conduit forming part of this invention with a variable valve arrangement such as is disclosed in Figures 16 and 1'7. At each circumferential gap of the longitudinal series of venturis there is a wall, such as those identified by the numerals III, H, 12, I3 and H forming therebetween fluid inlet channels I5, l6, I1, 18 and 18. A hollow shell or valve 88 is slidably mounted over the wall of the inlet duct ill and adapted for slidable engagement with the outer'terminal portions of said walls 10, II, I2, 13, H and the wall'82. Upon a slidable manipulation of-said valve 88, the number of said channels 15, I8 etc. exposed to and communicating with the inlet duct 8| can be varied in predetermined manner. Thus, in the position illustrated in Figure 16, the fluid entering duct 8| can enter the channels 15 and 18, whereas the channels 11, 18 and 19 are exposed to and communicate with the incoming cool combustion air. By moving the valve to the left, a greater proportion of the atomizing fluid flowing through duct 8| is permitted to enter the said channels. thereby supplying a greater number of venturis with the heated fluid medium,--and only a proing air, the final mixture ratio would be richer,

and conversely if theslide were moved to the right so as to admit'more cooling medium the final mixture ratio would be leaner. In this manner, not only may the degree of fixation be controlled whilethe gasifler is inoperation, but a greater degree of gasification will be efiected over alarger fuel range. v It should be noted that and process argherein repeatedlyurtferred to as being adapted for use with two fluid mediums of different temperatures, they are equally well adaptable for use with-asingle fluid medium, such as preheated air','-'a'n arrangement which is highly desirable in certain types of fuel-burning installations. For example, if the slide 88 of Figure 16 were moved to its extreme left posialthough our apparatus only preheated air allowed to enter the apparatus,thereby permitting the use of lower temperatures of the preheating medium for the production of a gas'in combustible proportions.

For the purp'ose'of producing a greater degree of homogeneity of the gaseous fluid as it leaves the last venturi and before it enters the intake manifold, we have devised a modification of the intermediate passageway between the last venturi of the flow conduit and said manifold. In Figure l8, the last venturi 83 having the serrated edge 84 leads into the chamber 85 containing an expanded portion adjacent the venturi and tapering downwardly to the manifold inlet diameter at 88. With such an arrangement, the discharge from the venturi 88, at its relatively high velocity, will cause the fluid to move in a swirling direction as indicated by the arrows, thereby causing the reverberation of the outer zone of the fuel stream and a more thorough mixing thereof. It should be noted that in this construction the expanded portion of the chamber 85 completely'surrounds the outlet end of the venturi 83 which protrudes into the chamber.

In the above description of the apparatus and process employed thereby, we have repeatedly referred to preheated atomizing air. There are many diiferent ways in which such air can be preheated, one being efiected by the construction shown in Figure 19. The shell or jacket 81 completely surrounds a portion of the outlet manifold 88 of an internal combustion engine, so that the air to be preheated can enter through the opening 89 to receive the heat through the walls of said manifold and enter the gasifying unit through the outlet 90. Other preheaters including various types of burners, can similarly be employed in conjunction with this invention.

It is obvious that our invention is adaptable to many uses in addition to its employement in internal combustion engines, such as in conjunction with open gas burners, industrial and domestic furnaces and such illuminating devices as the Welsbach mantle. Other and additional forms of apparatus and adaptations of the process can be employed beyond and in addition to those hereinbefore described, all within the scop of the appended claims.

What we claim is:

1. In an apparatus for converting a liquid fuel into a gaseous fluid, a flow conduit for-conducting therein an atomized fuel stream, the conduit progressively expanding in cross-sectional area in a plurality of stages from its inlet to its outlet terminal, an inlet port at each of said stages, certain of said ports containing serrated terminals, and two independent ducts each communicating with a plurality-of said ports, one of said ducts being for an atomizing medium and the other for combustion air.

2. In an apparatus for converting a liquid fuel into a gaseous fluid, a flow conduit for conducting therein an atomized fuel stream, the conduit progressively expanding in cross-sectional-area in stages from its inlet to its outlet terminal, the said outlet terminal of the conduit having a slightly constricted outlet opening; an inlet port at each ofsaid stagesfor the admission therethrough ofafluid medium for interpenetration with said stream; and an intermediate passage-' sectional area adjacent and partly surrounding said termnal portion and tapering to a reduced diameter at its juncture with the said duct.

3. In an apparatus for converting a liquid fuel into a gaseous fluid, a flow conduit for conducting therein an atomized fuel stream comprising a plurality of longitudinally disposed Venturi tubes with overlapping adjacent ends forming circumferential gaps therebetween, each succeeding venturi being of greater cross-sectional proportions than its preceding one, and two independent ducts each communicating with a plurality of said gaps, the inner overlapped edges of certain of said venturis being serrated.

4. In a method of gasifying aliquid fuel the step of spraying the fuel, introducing into one section of said stream at a plurality of portions thereof an atomizing fluid. and progressively expanding said section of the stream, introducing into a succeeding section of the stream at a plurality of portions thereofunheated combustion air and progressively expanding said latter section of the stream during its flow to an outlet terminal. I

' 5. In a method of converting a liquid fuel into a gaseous fluid the steps of spraying the fuel, inducing a flow of the resulting fuel stream through a low pressure region, introducing at such region a fluid medium preheated to a temperature above the vaporization point of the fuel at the prevailing pressure, introducing thereafter unheated combustion air, and progressively expanding the fuel stream co-mixed with the'combustion air introduced therein during its flow to an outlet terminal until the stream is of a temperature below the condensation point of the fuel at the prevailing pressure.

6. In a method of converting a liquid fuel into a gaseous fuel the steps of spraying the fuel, inducing a flow of the resulting fuel stream through a plurality of low-pressure regions, introducing at certain of said regions a fluid medium preheated to a temperature above the vaporization point of the fuel at the prevailing pressure, introducing thereafter at a plurality of points along the stream relatively cold combustion air for interpenetration and commingling therewith, and

gradually expanding said fuel stream at least throughout the entire portion thereof into which both the preheated fuel medium and the combustion air were introduced until the stream is of a temperature below the condensation point of the fuel at the prevailing outlet pressure.

''7. In a method of converting a liquid fuel into a' gaseous fluid the steps of first preheating an atomized fuel stream by introducing therein at a plurality of points therealong a relatively hot fluid medium, progressively expanding the resulting mixture, and then cooling the stream by introducing at a predetermined number of points thereafter a plurality of charges of relatively cold air, and progressively expanding the resulting mixture after the admission of each charge of cold air.

8. The method of converting a liquid fuel into a gaseous fluid, comprising, in combination, the steps of spraying the fuel, inducing a flow of the resulting fuel stream in a predetermined direction, increasing the velocity and decreasing the pressure of the said stream at a plurality of points therealong by restricting at such points its crosssectional area, introducing a plurality of said points, a fluid medium at a temperature above the vaporization point of the fuel at the prevailing pressure, progressively expanding the resulting mixtures after the introduction of said fluid medium at each of said points, introducing thereafter at the'remaining of said points relatively cold combustionair for interpenetration and corrnningling therewith, and progressively expanding the resulting mixtures after the introduction of said combustion air at each of said points.

9. In a method of converting a liquid fuel into a gaseous fluid, the steps of spraying the fuel,

inducing a flow of the resulting fuel stream' through a low-pressure region, introducing at such region a preheated atomizing fluid medium, thereafter diluting the stream at a plurality of points therealong with a cooling fluid medium, and progressively expanding the fuel stream after each introduction of said atomizing medium and said cooling medium and during its flow to an outlet terminal.

10. In a method of converting a liquid fuel into a gaseous fluid the steps of spraying the fuel, inducing a flow of the resulting fuel stream in a predetermined direction and. within a confined space, introducing therein at a plurality of sections therealong a fluid medium of a different temperature than that of the stream to cause a contraction of the high temperature or heatemitting fluid and an expansion of the low temperature or heat-absorbing fluid withinthe substantially confined region, thereby resulting in an intermingling of the constituents of both fluids, dividing the peripheral portion of the stream at certain of said sections into relatively flne streams, and directing said flne streams in" the general direction of the fuel stream.

11. In an apparatus for converting a liquid fuel into a gaseous fluid, a flow conduit for conducting therein an atomized-fuel stream, the conduit progressively expanding in cross sectional area in a plurality of stages from its in-' Venturi tubes through which the fuel stream is caused to flowseach tube having a restricted section at which the edge of the outlet of the preceding tube is positioned for optimum operation, the outlet end of certain of the tubes being serrated to present outlet edges directed substantially in the said longitudinal direction, whereby the said optimum operation is obtained by positioning the said serrated outlet edges at any portion of the said restrictedsection. I

13. In a device for subjecting a fuel to the action of a fluid medium for conversion into a gasi-- fled fuel stream, the combination according to claim 12 wherein the Venturi tubes are of progressively expanding proportions.

cnns'rna A. man. GEORGE L. REICHHELM. 

